Flexible cell support



Oct. 31, 1944. ER 2,361,743

FLEXIBLE CELL SUPPORT Filed March 5, 1943 3 Sheets-Sheet 1 FIGURE FIGURE3 INVENTOR.

EDWIN I. BUTLER AT TORNEY Oct. 31, 1944.

|-:. I. BUTLER 2,361,743

FLEXIBLE CELL SUPPORT Filed March 5, 1943 3 Sheets-Sheet 2 INVENTOR.

EDWIN I. BUTLER ATTO NEY 0d. 31, 1944. BUTLER FLEXIBLE CELL SUPPORTFiled March 5, 1943 3 Sheets-Sheet 3 INVEN TOR.

k. MKDOrm EDWIN I. BUTLER ATTORNEY Patented Oct. 31, 1944 Edwin I.Butler, Baltimor Glenn L. Martin Company,

c, Md., assignor to The Middle River, Md,

a corporation of Maryland Application March 5, 1943,. Serial No.478,125.

3 Claims.

This invention relates to a frame designed to interiorly support aflexible-walled cell, particularly those flexible cells. of natural. orsynthetic plastic materials for the transportation and storage of.gasoline. v

The use of a flexibleewalled. cell orv tank. fabricated from one or morelayers of plastic materials, has become almost universal in vehicles forthe transportation andstorage of fuel and oil. This type of fuelcontainer is desirable in vehicles, in which the structures are subjectto great stress and deflection. For example. in aircraft, it is commonpractice to store fuel in cavities in the wings of the plane. Thedeflection experienced by an airplane wing, of current construction iswell-known, so that it is obvious that the structural walls of thehollow spaces in the wings cannot be made sufficiently rigid to beliquid tight and retain gasoline. To installfabricated tanks in thesecavities is objectionable for two reasons, first, any adequate storagetank would add unnecessary weight to the structure and, second, it isdesirable to utilize every bit of space in the cavity for fuel storage.If a metal tank were built to occupy as much space as possible, it wouldthen be subject to the stress of the deformation of the exteriorstructure? The flexible-walled cell was developed to act as a containerfor fuel, the outer or side wall structure of the cavity functioning asthe retainer for the fuel container, and bearing the pressure load.

This flexible-walled cell may be of varied construction. Inits simplerform. it comprises one or more layers natural or synthetic plasticmaterials which are flexible but, inert to the action of any fuel thatmay be carried. Natural rubber and many of the so called syntheticrubbers or plastics have been used.

The cells used for militarypurposes are generally referred to as of theself-sealing type and consist of a plurality of layers of plasticmaterial bonded together with an intermediate, relatively thick layer ofcrude rubber or Vistenex, an isobutene polymer. These materials when incontact with gasoline swell and seal a bullet hole.

While the cells are flexible, they are formed to fit a particularshapecavity. Fromthe time they are removed from the fabricating moulds, tothe time they are installed in the retaining cavity, they are subjecttodamage from mishandling. Some ofthe plastics used are subject tocold-flow and in the self-sealing cell, it is imperative to preventcoldflow of the inner and outer layers of impregnated fabric or sheets of Iwith: a consequent distortion of the self-sealing layer.

To solve the above handling and servicing of these described support wasdeveloped.

An objectof. thisinvention is to provide a support for flexible-walledfuel cells to maintain their predetermined shape.

Another object of theinvention is to provide a support constructionwhich can be collapsed for insertion and removal through an accessopening in the cell.

Another objection is the provision of a hinged supporting structure oflight-weight, inexpensive but durable material.

The supporting frame of this invention maintains the shape of theplastic fabricated cell, to prevent cold-flow and other damage but willnot, of itself, damage the cell.

By means ofv this invention, the cell may be suspended from, a rack outof contact with all injurious materials and subject only to thosestresses that it was designed to withstand.

A further object of this invention is theprovision of a means forholding these flexible-walled fuel cells in position for service andrepair.

Further and other objects will become apparent from the description ofthe accompanying drawings which form a part of this disclosure and inwhich like numerals refer to like parts.

' In thedrawingsz- Figure 1 is a perspective View of the cell partly insection showing the supporting frame.

Figure 2 is a perspective view of the supporting frame.

Figure 3 is a section through aseaplane, hull showing the cell of Figure1 installed.

Figure 4 is a fragmentary view of the corner ofthe frame showing thecorner assembly.

Figure 5 is a fragmentary view showing a detail of a hinge.

Figure dis a fragmentary view showing a lower corner of the frame.

Figure '7 is a fragmentary view showing a detail of an upper corner.

Figure 8 shows the bottom assembly collapsed.

Figure 9 shows the top assembly collapsed.

Figure 10 shows the frame support assembly.

A flexible-walled cell or tank I, is shown in Figure 1, supported by aframe which embodies problems relating to the cells, the herein thisinvention.

The support or frame shown in Figure 2, consists of three pieces orassemblies generally indicated as A, B, and C.

The assembly A consists of a quadrilateral frame having similar sidemembers 2 and 3, each comprising strips 4 and 5 spaced by blocks 6, to

permit members I and 8 to be pivoted therebetween (see Figure 6).Members 9 and I are hinged to block II and to members so that they mayfold inwardly against members 2 and 3. The hinge construction of Figure5 is employed to make it possible to fold members 9 and Ill, and 2 and 3into a compact arrangement shown in Figure 8. Members I and 8 pivotabout one end and may be collapsed into the space between members 4 and5. In the particular installation, it should be noted that the axis ofthe hinge between members 3 and Ill, and 2 and 9 are arranged to permitthe folding of these members in the same plane. From the drawings, itwill be seen that the quadrilateral frame with the fourup-rightsupporting members can be folded into a compact bundle shown in Figure8. The double hinge H between members 9 and I0 may be reinforced by ahook strap l2.

A quadrilateral frame indicated as assembly B consists of members I3 andI 4, each of similar construction to members 2 and 3, consisting ofspaced strips I5 and I6 and spacer blocks IT. The fastening and foldingmechanism is similar to that described for the quadrilateral frame ofassembly A. This frame is illustrated in its folded position in Figure9. The assembly indicated as C is shown in Figure 10, consists of a barl8 having eye bolts l9 secured thereto. This bar is designed to fit intonotches 20 in the frame B.

Figure 4 shows a detail that is typical of any of the top corners. Theupper end of member 8 slides into position between members I 5 and I6spaced by block I! having a hole positioned to receive pin 23 on member8. These pins prevent assembly A from pulling away from assembly B whenlifted by assembly C. A latching means indicated by 24, which may be abolt or any equivalent structure, secures member 8 from inadvertentlypivoting to the position shown as 8'.

Figure 5 shows an enlarged view of a double hinge mechanism that permitsmembers 9 and to double back and collapse flat on one another. The blockII is pivotally secured by pins 25 in notched ends of members 9 and In.

Figure 6 shows in detail the spacing of members 4 and 5 by block 6 topermit and facilitate the pivoting of member 8. The structure shown isrequired due to the odd angle at the corner of the particular cell usedfor illustrating the invention, but the construction is adaptable to anytype cell that may need to be supported.

Of the many materials that may be used in the construction of thisframe, plywood is preferred due to its relatively high strength, lowcost and ease of fabrication. Metal, of course,

could be used, but would only be considered where itmight be desired toleave the frame in the cell, when the cell is filled with the liquid.Many of the sheet plastic materials are easily fabricated and couldreadily be used.

In operation, the folded assembly A shown in Figure 8, is insertedthrough the access opening in the cell, oriented, and then thequadrilateral frame extended and secured by the strap hooks I 2.Assembly B, F'gure 9, is then similarly positioned in the cell. Thespacers 1 and 8 are pivoted into place to hold the quadrilateral framesspaced properly and the corners are secured in the manner described inconnection with Figure 4. Assembly C is then inserted and secured in thenotches in assembly B. It will be noted that the notches for bar C willbe located approximately in the plane of the center of gravity of theassembly.

The cell is thus fully extended and supported in its predeterminedshape, but the frame can be handled quite readily and crated forshipping.

In field service, at the operation bases, where it is necessary toremove the cells from the retaining structure for service and repair,the

frame may be inserted in the cell when removed from the craft and thecell suspended from a rack for repair. The cell will be out of possibledanger until it is desired to re-install it in the sea plane.

The above description of the invention is intended to set out a singleembodiment of the invention which is essentially the frame to supportthe cell. It is obvious that the cell herein described could be adaptedto any of the many shapes now in use with the same advantages, in

any type of vehicle. It is to be understood that certain changes,alterations, modifications and substitutions can be made withoutdeparting from the spirit and scope of th appended claims.

I claim:

1. An articulated frame structure ada ted to conform with the internaldimensions of a flexible-walled fuel cell having an access opening inone side thereof, said structure comprising members forming twoquadrilateral frames, conforming with the internal dimensions ofopposite cell walls, each of said quadrilateral frames having two endmembers each having a slot formed therein extending substantially thelength of said member, side members extending between the ends of saidend members and hingedly'secured thereto at the end thereof, to form aquadrilateral frame, said side members being hinged intermediate theends to permit folding of said frame, spacer members pivotally securedto said end members at the ends thereof and adapted to fold within saidslots, a second quadrilateral frame of substantially the sameconstruction as said first mentioned form, having similar slots adaptedto receive and retain the ends of said spacer members to form saidsupporting structure for said flexible walled cell.

2. An articulated frame structure adapted to conform with the internaldimensions of a flexible-Walled fuel cell having an access opening inone side thereof, said structure comprising members forming twoquadrilateral frames, conforming with the internal dimensions ofopposite cell Walls, each of said quadrilateral frames having two endmembers each havinga slot formed therein extending substantially thelength of said member, side members extending between the ends of saidend members and hingedly secured thereto, to form a quadrilateral frame,said side members being hinged intermediate the ends to permit foldingof said frame, spacer members pivotally secured to said end members atthe ends thereof and adapted to fold within said slots, a secondquadrilateral frame of substantially the same construction as said firstmentioned form, having similar slots adapted to receive and retain theends of said spacer members to form said supporting structure for saidflexible walled cell, a supporting member adapted to engag said endmembers, so positioned as to extend across the access opening in thecel1 wall and means on said supporting member whereby the frame and cellmay be lifted.

3. An articulated frame structure adapted to conform with the internaldimensions of a flexible-walled fuel cell having an access opening inone side thereof, said structure comprising members forming twoquadrilateral frames, conforming with the internal dimensions ofopposite cell walls, each of said quadrilatera1 frames having two endmembers each having a slot formed therein extending substantially thelength of said member, side members extending between the ends of saidend members and hingedly secured thereto, to form a quadrilateral frame,said side members being hinged intermediate the ends to permit foldingof said frame, spacer members pivotally secured to the ends of said endmembers and adapted to fold within said slots, a second quadrilateralframe of substantially the same construction as said first mentionedform, having similar slots adapted to receive and retain the ends ofsaid spacer members to form said supporting structure for said flexiblewalled cell, a supporting member adapted to engage said end members sopositioned as to extend across the access opening and lie substantiallyin a vertical plane with the center of gravity of the frame and cellassembly, means on said supporting member whereby the frame and cellassembly may be lifted.

EDWIN I. BUTLER.

